Process of producing prussic acid.



0. LIEBKNECHT.

PROCESS 0F FRODUCING FRUSSIC ACID.

APPLICATION FILED MN.27|1917.

1,235,343, Patented July 31,1917.

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OTTO LIEBKNECHT, O-F FRANKFORTONTHE-MAIN, GERMANY, ASSIGNGR TG THE ROESLER @t HASSLACHER CHEMICAL COMPANY, F NEW' YORK, N. Y., A. COR- PORATION 0F NEW YORK.

PROCESS 0F PRODUCING PRUSSC ACD?.

Application filed January 27, 191'?.

To all whom 1f may concern.'

Be it known that I, OT'ro LIEBKNECHT, a subject of the German Emperor, and resident of Frankfort-on-thedvlain, Germany, have invented certain new and useful lm provements in Processes of Producing Prussic Acid, of which lthe following is a specilication.

1 tion. What isknown in this respect is that some reactions may be promoted by the application of pressure while others can be checked thereby; and we further know 'that v in singular cases, reduction of pressure has a favorable effect upon the reaction.

There have beenv presumptions made up toV the present that the application of pressure to a gas mixture suitable for the synthesis of prussic acidiwhile being subjected t0 heat, such for instance, as prevails in a high tension arc, will exert a beneficial effect on the reaction, but such presumptions'or suggestions have not yet, as far as I am aware, been substantiated in a process warranting its industrial application. n

I shall describe, by way of example, how l carry out my new process and for the better understanding of my invention l refer to the accompanying drawing, which illustratesfone type of apparatus suitable for the practice of my invention. Figure l isa vertical section through a portion of the reaction chamber; Fig. 2 is a sectional view of the apparatus shown in Fig. l along the line 22; and Fig. 3 is a side elevation of the complete apparatus, parts bein shown in section.

imilar letters of reference'indicate' similar parts throughout the several views.

a indicates the furnace chamber proper and a the furnace wall; t indicates a side chamber connecting with the chamber c and containing an electrode @with its insulation tube d, e `indicates a gas tight packing; pipes g1, g2, h1 and h2 are provided to introduce the gases into chamber b; pipe f Serves as an inlet into insulating tube o?.

Specification of Letters Patent.

In the drawing,`

llatented July Si, 12H7.

serial no. 145,020.

The pipes are preferably disposed so as to introduce the gases conducted by them tane gentially to the walls of chamber b or tube d, respectively, as shown in Fig. i2. The details ofthe foregoing apparatus and the operation thereof have already been described and claimed in my copending application Serial No. 145,019, filed January 27, i917.

In Fig. 3, l have shown the complete apparatus assembled. Connecting with furnace chamber a at one end is a pipe z' for supplying the reacting gases. Pipe j at the opposite end from pipe z' serves as an exit for the products'of the reaction. c indicates a' spring controlled check valve which may be set to maintain any d( red pressure in furnace chamber a. As described in my copending application l pass .'hrough the pipes f, gl and hl, and g2 and t?, gases either entirely free from carbon or which contain the latter only in such form that it will not be reduced from its compound under the conditions of the operation.

Such. gases are for instance nitrogen, can bon monoxid or a mixture of these, either with or without hydrogen, in the form of producer gas; these gases introduced into the side-chamber serve, as already described in my copending application, to avoid what otherwise would taire place, viz., the deposition of carbon on the electrodes owing to decomposition of the applied hydrocarbon by heat which would finally cause short cir cuits. llt is obvious that these gases finally mix with thereactiongases which. 1' intro duce into the reaction chamber proper under pressure through pipe e" or other suitable means, and when introduced into the side chambers, they are at least under the pressure prevailing in the reaction chamber.

l have found that the thermal treatment of the gases under pressure in chambera, produces excellent results both with respect to the materials used and the energy applied. I have ascertained that a mixture which l obtained in approximately the 'manner described above, and comprising of carn bon monoxid, 8.3% methane, 33.7% of Vhydrogen and 42.7% of nitrogen yielded more than 50 gms. of HCN per kilowatt hour if treated 'at a pressure or 1.6- atmospheres, whereas a mixture of the same composition at 'atmospheric pressure yields only 40 gms. per kw. hour. It is obvious therefore, that the maintenance of a moderate pressure in the reaction chamber during the reaction is of great importance. The infiuence 'pres sure is thus shown to have on the reaction is all the more interesting inasmuch as heat, together with pressure, is known to favor the deposition of soot, but such deposition is not present in my process, or is at least reduced to such a minimum that it cannot any longer be considered a source of danger or disturbance. The reason for this absence of soot during my process is not yet fully ascertained and various reasons muy be cited for this; fact, for instance that the gas mixture, is subjected to a greater degree to a kind of local heating by the electric are and mames in the presence of gases incapable of partaking in the reaction, whereas in all the cases where a considerable degree of soot formation is obtained, pure hydrocarbons are subjected to heat from outside.

I claim.:

The prowess of making hydrocyanic acid by subjecting a gaseous mixture of a hydrocarbon, hydrogen and nitrogen to the in1i ence of heat from a high voltage nrc, at n pressure of approximately 1.6 atmospheres.

In testimony whereof I have signed my nameto this specification in the presence of two subscribing witnesses.

OTTO LIEBKNECHT.

rWitnesses JEAN GRUND, HARRY E. CARLSON. 

